<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #box{
            width: 200px;
            height: 200px;
            background-color: red;
        }
    </style>
</head>
<body>
    <div id="box">

    </div>

    <script>
        function enablelongtap(ele){
            let event=new CustomEvent("长按")
            let timer=0;
            let isLongTap=false;
            ele.addEventListener("mousedown",()=>{
                isLongTap=true;
                clearTimeout(timer);
                timer=setTimeout(()=>{
                    if(isLongTap){
                        ele.dispatchEvent(event);
                    }
                },500)

                

            })
        }



        {
            let box=document.querySelector("#box");
            box.addEventListener("长按",()=>{
                console.log("这是一个长按事件")
            })
        }
    </script>
</body>
</html>